1. Technical Field
The present invention relates in general to an improved data recording device, and in particular to improving the fabrication of miniature data recording devices. Even more particularly, the present invention relates to solving various problems associated with the manufacture and assembly of the components of miniature data recording disk drives, such as the head stack assembly.
2. Description of the Prior Art
Hard disk drive devices have been used as a data recording device of a personal computer. With the advance of technology, a data recording density has been increased, and a size of a hard disk, i.e., a magnetic data recording disk and a size of a housing have been decreased. The examples of the size, i.e., a diameter, of the previous hard disk are 3.5 inches (95 mm), 2.5 inches (65 mm), 1.9 inches (48 mm) and 1.3 inches (34 mm).
Referring now to FIG. 1, the structure of a prior hard disk drive device 1 is shown. The major parts of device 1, such as a hard disk 2, a head stack assembly 3, a magnet 4, an outer crash stop 5 made of rubber, an inner crash stop 6 made of rubber, a flexible cable 7 and a control unit 8 mounted on the flexible cable 7, are mounted within a housing 9. The hard disk 2 is supported by a shaft 10 which is rotated by a spindle motor, not shown. The head stack assembly 3 is pivotally moved around a pivot point 12. A voice coil 11 is mounted on the head stack assembly 3. The voice coil 11 and the magnet 4 constitute a voice coil motor. A current supplied to the voice coil 11 is controlled to move the head stack assembly 3 along a radial direction indicated by an arrow xe2x80x9cAxe2x80x9d to position a head on a head slider assembly 13 on a data recording track on the hard disk 2 to read data from the data recording track or to write the data into the data recording track. Electrical conductive wires on the flexible cable 7 connect the head and the voice coil 11 to the control unit 8.
FIG. 2 shows a structure of the prior art head stack assembly 3. A plurality of head gimbal assemblies 14 and spacers 15 are stacked on a carriage 16. A screw 18 is used to align the head gimbal assemblies 14, the spacers 15 and the carriage 16. A pivot cartridge 19 is inserted into the aperture and is fixed by a nut 20. A circuit substrate 21 connected to the flexible cable 7 is fixed to the carriage 16 by a screw 22. Each of the head gimbal assembly 14 includes an extended plate 23 on which connecting pads, not shown, electrically connected to the head are arranged. The extended plate 23 is cantilevered from the head gimbal assembly 14. The connecting pads, not shown, which are connected to the connecting pads of the extended plate 23, are arranged on the circuit substrate 21 and are connected to electrically conductive wires on the flexible cable 7. Electrically conductive wires 26 of the voice coil 11 are connected to connecting pads, not shown, on the circuit substrate 21.
Head gimbal assembly 14 has a plurality of parts including an arm assembly 24 and a suspension load beam 25. The arm assemblies 24 and load beam 25 of each of the head gimbal assemblies 14 must be aligned in order to precisely align each of the heads with respect to a center of the pivot point. In the larger, prior art hard disk drive devices (such as 95 mm form factor and 65 form factor), an external positioning jig is used to align the arm member 24 and the suspension load beam 25 since the size of the head stack assembly 3 is relatively large. See Japanese patent application 9-264596 (IBM Docket No.JA9-97-161), assigned to the assignee of the present invention. It is noted that the form factor represents the outer size or dimension of the housing of the hard disk drive device. The 95 mm form factor indicates the size, i.e., a width, a length and a height of the housing containing the 3.5 inch (95 mm) hard disk, and the 65 mm form factor indicates the size, i.e., a width, a length and a height of the housing containing the 2.5 inch (65 mm) hard disk.
The smaller hard disk drive devices, such as the 34 mm form factor (the size of the housing including the 34 mm (1.3 inches) hard disk) or the 27 mm form factor (the size of the housing including the 27 mm (1.0 inches) hard disk), have been recently developed. One problem associated with small size hard disk drive devices is that it is difficult to assemble the head gimbal assembly 14 on the carriage by using the external positioning jig since the size of the head gimbal assembly 14 is very small. Therefore, it is desirable to assemble the head gimbal assembly 14 on the carriage without using the external positioning jig.
Another problem associated with small disk drive devices is that it is difficult to assemble the discrete, inner and outer crash stops 5, 6 within the small space of the housing. A third problem with small disk drive devices is that it is difficult to affix the circuit plate 21 to the carriage 16 with the screw 22. A fourth problem with small disk drive devices is that it is difficult to connect the wires of the voice coil 11 to the connecting pads on the circuit substrate 21. Thus, there is a need to improve the ability to fabricate and assemble miniature hard disk drive devices.
A head stack assembly for a data recording disk drive has a carriage on which a coil is mounted. The carriage has a first surface and a second surface. A first head gimbal assembly is mounted on the first surface, and a second head gimbal assembly is mounted on the second surface. A datum member is formed on each of the surfaces of the carriage. The datum member is used to position each of the head gimbal assemblies on their respective surfaces. The datum member has two pins that engage apertures in the head gimbal assemblies. A pivot member is located in a separate aperture between the pins such that the head stack assembly is balanced at the center of the pivot member.
Accordingly, it is an object of the present invention to provide an improved data recording device.
It is an additional object of the present invention to improve the fabrication of miniature data recording devices.
Still another object of the present invention is to provide techniques for solving various problems associated with the manufacture and assembly of the components of miniature data recording disk drives, such as the head stack assembly.
The foregoing and other objects and advantages of the present invention will be apparent to those skilled in the art, in view of the following detailed description of the preferred embodiment of the present invention, taken in conjunction with the appended claims and the accompanying drawings.